Used to use Rock Oil's chain lube.
As far as corrosion protection, I use Boeshield T9. I spray everything under the motor cowl, except for moving rubber bits (belts and such.)
T9 seems to work pretty well on everything except crescent wrenches. For some reason, if you have a crescent wrench and *think* about seawater, it will corrode to worthlessness within a few days.